Commit 7df652f1 authored by Mario Limonciello's avatar Mario Limonciello Committed by Wen Zhiwei
Browse files

ACPI: CPPC: Add support for setting EPP register in FFH 

stable inclusion
from stable-v6.6.55
commit 29dbea4c56df235a43e912aba1e49f9b2c53d25b
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IB0MX4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=29dbea4c56df235a43e912aba1e49f9b2c53d25b



--------------------------------

[ Upstream commit aaf21ac93909e08a12931173336bdb52ac8499f1 ]

Some Asus AMD systems are reported to not be able to change EPP values
because the BIOS doesn't advertise support for the CPPC MSR and the PCC
region is not configured.

However the ACPI 6.2 specification allows CPC registers to be declared
in FFH:
```
Starting with ACPI Specification 6.2, all _CPC registers can be in
PCC, System Memory, System IO, or Functional Fixed Hardware address
spaces. OSPM support for this more flexible register space scheme
is indicated by the “Flexible Address Space for CPPC Registers” _OSC
bit.
```

If this _OSC has been set allow using FFH to configure EPP.

Reported-by: default avatar <al0uette@outlook.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218686


Suggested-by: default avatar <al0uette@outlook.com>
Tested-by: default avatar <vderp@icloud.com>
Tested-by: default avatar <al0uette@outlook.com>
Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20240910031524.106387-1-superm1@kernel.org


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarWen Zhiwei <wenzhiwei@kylinos.cn>
parent 89e26895

drivers/acpi/cppc_acpi.c

+9 −1
Original line number Diff line number Diff line
@@ -100,6 +100,11 @@ static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); 
				(cpc)->cpc_entry.reg.space_id ==	\

				ACPI_ADR_SPACE_PLATFORM_COMM)



/* Check if a CPC register is in FFH */

#define CPC_IN_FFH(cpc) ((cpc)->type == ACPI_TYPE_BUFFER &&		\

				(cpc)->cpc_entry.reg.space_id ==	\

				ACPI_ADR_SPACE_FIXED_HARDWARE)



/* Check if a CPC register is in SystemMemory */

#define CPC_IN_SYSTEM_MEMORY(cpc) ((cpc)->type == ACPI_TYPE_BUFFER &&	\

				(cpc)->cpc_entry.reg.space_id ==	\
@@ -1514,9 +1519,12 @@ int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable) 
		/* after writing CPC, transfer the ownership of PCC to platform */

		ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE);

		up_write(&pcc_ss_data->pcc_lock);

	} else if (osc_cpc_flexible_adr_space_confirmed &&

		   CPC_SUPPORTED(epp_set_reg) && CPC_IN_FFH(epp_set_reg)) {

		ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf);

	} else {

		ret = -ENOTSUPP;

		pr_debug("_CPC in PCC is not supported\n");

		pr_debug("_CPC in PCC and _CPC in FFH are not supported\n");

	}



	return ret;